Many attempts have been made to obtain synthetic resins having excellent physical properties by blending synthetic resins of different properties and eliminating drawbacks of the respective synthetic resins.
Synthetic resins having different properties, however, lack compatibility, while it is often impossible to obtain excellent physical properties by blending compatible synthetic resins.
For the compatibilization of synthetic resins which lack compatibility, there are many methods including use of a compatibilizer, use of a random copolymer, use of pressure effect, etc. Methods utilizing compatibilizers use styrenic resins containing epoxy groups disclosed in JP-A-60-221459 and JP-A-61-293260. (the term "JP-A" as used herein means an "unexamined published Japanese patent application).
In many cases, however, even these compatibilizing means produce insufficient results, and therefore, there has been a demand for a better means for compatibilization.